Clutch reservoir cap
 

Is it just me or is it odd that the cap has a pressure relief in it. Its brake fluid in there so wouldn't moisture be getting into the system through there. Any disadvantage to sealing it up? Does anyone make a cap that does seal it?

Someone has to have an opinion

As long as the cap is not removed, it is a sealed system. You have the bellows that moves with the fluid level .. providing the sealing member ... the top side of the Bellows is vented via the cap......don't plug it .... Hope this helps

I follow you but wouldn't a vented cap allow moisture into the system. Or is it 100% a one way system and if it was once pressure was vented out would it not create a minor vacuum in the system?

The cap is sealed from the bellow down. The area above the bellow is vented. No air can get into the system. Gm has been doing this for years. No need to rethink the wheel.

LOL fine. So my question now is what is the purpose of the bellow? Why couldn't it be the same setup as the brake fluid reservoir?

brake fluid doesn't recirculate, clutch fluid does.
is there a problem with it, or you just happen to be wondering about this?

Just wondering more than anything. The reason I posed the question is because recently I had changed the fluid and the car sat for awhile without being driven and I noticed that it still darkened up as if moisture was hitting it.

The fluid darkening up is not moisture it is clutch dust. Read Ranger's sticky at the top of the forum titled Clutch Pedal Issues - How to prevent and cure.

:cheers:

I agree on it being clutch dust but why would it darken up if the car isn't being driven? Ponder that one my friend lol

The brake fluid reservoir does have a bellows that's vented on the topside like the clutch master. I've always assumed that the bellows was designed to seal the fluid from the air but still accomodate a pressure differential between the reservoir and the atmosphere when the fluid level in the reservoir changes.

I understand thats the purpose of the bellow but wouldn't it be better to have more pressure in the system? Could the flex in the bellow be causing a loss in hydraulic pressure in the system.

No, the reservoir draws from the bottom, and unless the reservoir goes completely empty (you have a leak), it will purge itself of air, as long as there is the volume of fluid available to replace the air.

Using Rangers method, the last thing you do is pump the pedal, so after the procedure, the fluid is always going to be a little darker than out of the can. The first pedal pump brings fluid from the clutch slave cylinder back up to the reservoir.
Still wondering?:D

Clutch Debate
 

It is a 5 minute process. Great responses to the questions. That is why I'm a Member!!

dcamick:cheers:

The reason I asked the whole question is for 2 reasons:

1) Even with crystal clear fluid these cars under an extremely hard launch lose the clutch and was wondering could this be to partial loss of hydraulic pressure and so the clutch doesn't have enough clamping force leading to it slipping and glazing itself.

2) This was my clutch fluid recently after doing the ranger procedure a solid 5 times and then leaving the car to sit without touching it whatsoever for 5 days. Pedal was never touched. The fluid is darker and as you can see something is floating in it. Also I do the Ranger method all the time. Sometimes I do it just for the hell of doing it even when the fluid looks good just to make sure its extra clean. So no need to preach to the choir on swapping the fluid every little bit.

http://i65.photobucket.com/albums/h2...k/63c29dc2.jpg



Also as a side note if I remember correctly my E46 M3 used one reservoir for both brake fluid and clutch fluid and it had no bellow or any sort.

What are those granules of poo at the bottom of your reservoir? When I change my fluid, I see dark specs but not what I see in your pictures. Maybe it's an illusion.

Clumped up clutch dust I guess. Its beyond me how dust gets in yet no fluid gets out.

I was told by a parts guy that due to humidity/moisture, it will turn black just sitting for a period of time. I bought my 2009 Z06 with 6000 miles a few months ago from a Cadillac dealer in Phoenix AZ who got it at auction from Ohio, where it was originally sold. I'm assuming it was parked most
of the time in Ohio. When I was changing out the fluid (thank you Ranger) I couldn't see any dust
particles as are shown in Ranger's excellent video. I believe that both factors can darken the clutch fluid. Hope this doesn't add confusion to the already
perplexing issue of why GM has allowed this
engineering glitch to be. Also, there is no "perfect" seal when the cap is on properly so moisture can find it's way inside due to the many fluctuations in temperature in an engine compartment.